Herbicide resistant seed carriers and process for manufacture thereof

ABSTRACT

Localized deposit of activated carbon-vermiculite mixture around seeds gives significant protection against certain pre-emergent herbicides. The mixture can be compressed in tablet form with a liquid fertilizer binder, or incorporated in water soluble mats, and permits precision field seeding with good protection from pre-emergence application of herbicides.

United States Patent Johnson et al.

[ Mar. 14, 1972 [54] HERBICIDE RESISTANT SEED CARRIERS AND PROCESS FOR MANUFACTURE THEREOF {72] Inventors: Paul E. Johnson; Clarence G. Ilaugh; George F. Warren, all of W. Lafayette, Ind.; Bernard A. Kratky, Sullivan, Wis.

[73] Assignee: Purdue Research Foundation [22] Filed: Dec. 9, 1969 [211 App]. No.: 883,483

[51] Int. Cl .......,A0lc H06 [58] Field otSearch ..47/1.9, 57.6, DIG. 9, DIG. 10, 47/58, 56; 71/D1G. l, 1,27

[56] References Cited UNITED STATES PATENTS 2,988,441 6/1961 Pruitt ..7l/27 3,561,159 2/1971 Adams ..47/57.6

2,671,985 3/1954 Vogelsang ..47/57.6 2,909,869 10/ I 959 Dresser ..47/ 58 3,077,700 2/1963 Tukacs ..47/1 3,168,796 2/1965 Scott et al.... ..47/l 3,341,318 9/ 1967 Chilton ..47/9 X FOREIGN PATENTS OR APPLICATIONS 599,445 3/1948 Great Britain ..47/58 617,040 1/1949 Great Britain ..47/56 Primary Examiner-Robert E. Bagwill Attorney-John R. Nesbitt [57] ABSTRACT Localized deposit of activated carbon-vermiculite mixture around seeds gives significant protection against certain preemergent herbicides. The mixture can be compressed in tablet form with a liquid fertilizer binder, or incorporated in water soluble mats, and permits precision field seeding with good protection from pre-emergence application of herbicides.

1 Claims, 12 Drawing Figures PAILIIIEIIIIIIII I4 I972 3,6d8AO9 SHEET 2 [IF 3 I4 0,2,4,a,I6=LB./A HERBICIDE A g LSD 5v. & o I-' 10- g 2 I a 8 E LL WITH WITHOUT CARBON-VERMICULITE MIXTURE INFLUENCE OF THE CARBON-VERMICULITE MIXTURE ON HERBICIDE A TOXICITY TO CUCUMBERS IN THE GREENHOUSE CARBON-VERMICULITE MIXTURE INFLUENCE OF THE CARBON-VERMICULITE MIXTURE ON HERBICIDE B TOXICITY TO CUCUMBERS IN THE GREENHOUSE.

FIG. 7

LSD 5% g 24 .4 g 2.0 0 5 1,6 5% LL 1.2

g 0.8 E o 0.4

' WITH WITHOUT CARBONVERMICULITE MIXTURE INFLUENCE OF THE CARBON-VERMICULITE MIXTURE ON HERBICIDE B TOXICITY TO TOMATOES IN THE GREENHOUSE,

FIG. 6

7w O0,5,IJ2,4,8=LB./A HERBICIDE B 5 I LSD 5% a e o b I!) 2- 2 [E L) 1..

WITH WITHOUT CARBON-VERMICULITE MIXTURE INFLUENCE OF THE CARBON-VERMICULITE MIXTURE ON HERBICIDE B TOXICITY TO SOYBEANS IN THE GREENHOUSE.

FIG. 8

IN'VEN'IOR. PAUL E. JOHNSON CLARENCE G. HAUGH BY GEORGE F. WARREN BERARD A. RATK ATTORNEY NUMBER OF HILLS WI TH LIVE PLANTS NUMBER OF PLANTS PAIENIEUIIAR 14 I972 PROTECTION OF TOMATO SEEDLING FROM HERBICIDE DAMAGE IN ACTIVATED CARBON-VERMICULITE WAFERS,

FIG. 9

D :DIRECT SEEDED W=WAFER D D D DJ 0 J is E M 0 Q4 9U 90: a: 5 L 9% I- EE m a) Z CELLI m0: m 0 EL LUI-U m U %[I] I I NUMBER OF HILLS PER PLOT WITH LIVE TOMATO PLANTS 57 DAYS AFTER SEEDING.

FIG IO FIG. 12

INVENTOR. PAUL E JOHNSON CLARENCE G HAUGH GEORGE F WARREN BE NARD A KRATK o ATTOR NEY BACKGROUND OF THE INVENTION Carbon has long been used as an adsorbent for various types of toxic agents. It has previously been used on soils with phytotoxic amounts of various herbicides present.

The inhibition of the crop plants on these soils was greatly reduced because much of the herbicide was adsorbed and no longer was toxic to the crop plants. However, in most cases the herbicide was no longer toxic to the weeds either. In effect, incorporation of carbon into the soil is only important as a method of detoxifying herbicide residues in that soil. Carbon has also been applied in l-% ft. bands in herbicide treated soil. Again crop protection was observed, but weed control was not obtained in the l-% ft. bands. The end result was a method no more effective in weed control than spraying bands of herbicide between the rows but not over them. Ripper, as reported in Proceedings of the Third British Weed Control Conference, British Weed Control Council, 86 Strand, London WC. 2, (Nov. 6, 7, and 8, 1956), sprayed a 2 in. band of adsorbent over the seed row at a depth midway between the seed (which was l-r 2 in. deep) and the soil surface. The crop plants gained selectivity over the herbicides and good weed kill was obtained when the herbicide was applied to the soil surface. However, any system of protection which allows treated soil to contact the shoot zone as that mentioned above by Ripper subjects the plant to possible damage from uptake of the her bicide. Since Rippers study, others have sprayed narrow bands of carbon over crop rows before herbicide application. Again, protection was noted, but use of this method leads to weeds in the row where the adsorbent band was applied.

Another problem with these carbon bands has been that on soils commonly found in the midwest a high degree of crusting is obtained which often inhibits or prevents seed emergence. These bands are also subject to erosion thereby extending the herbicide protective effects away from the seeds.

Up to the time of this invention no commercially satisfactory solution has existed to protect seeds from pre-emergent herbicide application.

BRIEF SUMMARY OF THE INVENTION It is an object of this invention to provide a seed protective medium that facilitates emergence of seeds when used in conjunction with a pre-emergent herbicide applied for weed control.

It is another object of the invention to provide a seed carrier that permits precision seeding and which has good herbicide resistance combined with high speed emergence performance.

THE DRAWINGS FIG. 1 is two bar graphs showing stand counts and fresh weights for given rates of application of Herbicide A for a given cucumber seed group.

FIG. 2 is two bar graphs showing stand counts and fresh weights for given rates of application of Herbicide A for a given tomato seed group.

FIG. 3 is two bar graphs showing stand counts and fresh weights for given rates of application of Herbicide A for a given beet seed group.

FIG. A is a bar graph showing influence of the carbon-vermiculite mixture on Herbicide A Toxicity to Tomatoes in the Greenhouse.

FIG. 5 is a bar graph showing influence of carbon-vermiculite mixture on Herbicide A Toxicity to Cucumbers in the Greenhouse.

FIG. 6 is a bar graph showing influence of carbon-vermiculite mixture on Herbicide B Toxicity to Tomatoes in the Greenhouse.

FIG. 7 is a bar graph showing influence of the carbon-vermiculite mixture on Herbicide B to Cucumbers in the Greenhouse.

FIG. 8 is a bar graph showing influence of the carbon-vermiculite mixture on Herbicide B Toxicity to Soybeans in the Greenhouse.

FIG. 9 is two bar graphs showing protection of tomato seedlings from Herbicide B damage in activated carbon-vermiculite wafers.

FIG. 10 is a bar graph showing number of hills per plot with live tomato plants 57 days after planting.

FIG. 11 is a perspective view of a seed protective wafer.

FIG. I2 is a perspective view of a water soluble mat embodying the activated carbon-vermiculite mixture.

DETAILED DESCRIPTION OF THE INVENTION It has been found that a satisfactory herbicide resistant seed protective medium may be provided by making holes in the soil to be planted, placing seeds at the bottom of such holes and then filling the holes to the level of the soil surface with about 1.7 grams of an activated carbon-vermiculite mixture (these filled holes are sometimes hereafter referred to as hills). The carbon-vermiculite mixture is prepared by thoroughly mixing one pound of activated carbon with three liters of vermiculite. The commercial vermiculite used weighed 156 grams per liter. Of course, any anti-crustant material, either organic, such as sawdust, or inorganic, such as vermiculite, will give satisfactory results.

Tests were conducted and the following six crops were raised: the Hawkeye variety of soybean (Glycine max L.), the Bouncer variety of tomato (Lycopersicum esculentum Mili.), the Detroit Dark Red variety of beet (Bela vulgaris L.), the Harrison variety of barley (Hordeum vulgare L.), the Wisconsin SMR-l 5 variety of cucumber (Cucumis sativus L.) and the Greenback YR variety of cabbage (Brassica oleraceae L), The hills were placed 1 inch apart in rows 10 feet long. The rows were in sets of three, such that they were 10 inches apart and each set of rows was 5 feet apart. Soybeans, tomatoes, and beets composed one set of three rows while cabbage, barley and cucumber composed the other set. l-butyl-3-(3,4 dichlorphenyl-l-methylurea (hereafter called Herbicide A") (4 percent granular) was applied on the day of planting at rates of O, 4, and 12 pound active/Acre both with and without the carbon-vermiculite mixture. Weed counts were taken 22 days after planting. Stand counts with the number of hills having live plants were taken 22 days after planting. Fresh weights were taken after 40 days. A completely random analysis was performed for each crop. There were four replicates of each treatment.

Another field experiment was conducted on the same farm on an Ocltly silt loam soil which contained a Li percent organic matter. No herbicides were used on this site the previous year.

A split plot design with four replicates arranged in a randomized complete block was used for each of four crops. The whole units were herbicide treatments and the sub-units were carbon treatments. Two seeds were planted in each hill and the hills were 6 inches apart in 10 foot rows. Soybeans, tomatoes, cucumbers, and barley were the crops planted. A row of the crop without protection was planted 20 inches from a row with the carbon-vermiculite protection. The herbicide rates were 8 pound active/Acre of Herbicide A (4 percent granular), and 2 pound active/Acre percent wettable powder) of 2-chloro -4, 6-bis(ethylamino) triazine (hereafter called (Herbicide I3), and a no herbicide treatment was included. Weed counts were taken l9 days after planting. The plots were hand weeded after the weed counts were taken. Counts of hills with live plants were made 15 days after planting and fresh weights were taken 48 days after planting.

A greenhouse experiment was conducted to further aid in the determination of the protection afforded by the activated carbon-vermiculite mixture.

Sixteen ounce plastic pots with greenhouse soil were seeded with various crops such that half received the carbon-vermiculite protection as described above and the other half were direct seeded and not protected. Herbicide B (80 percent wettable powder) was applied to cucumbers, soybeans and tomatoes at 0, k, 1, 2, 4, and 8 pound active/Acre. Herbicide A (4 percent granular) was applied to cucumbers and tomatoes at 0, 2, 4, 8, and 16 pound active/Acre. Four replicates of each herbicide rate with and without the carbon-vermiculite treatment were included. Fresh weights were taken 22 days after planting. A completely random analysis of the data was performed.

This may be attributed to the rain washing the carbon away from the immediate area of the crop plants and desorbing some of the herbicide resulting in protection of the weeds. However, protection of tomatoes at 12 pound/Acre of Herbicide A, with good weed control, vividly demonstrated the compatibility of weed control and crop protection with this method.

in the field experiment where 2 pound/Acre of Herbicide B and 8 pound/Acre of Herbicide A were used on a lighter soil llnprotected barley and soybeans were tolerant to 4 and 12 10 excellent weed control was obtained.

TABLE 2 [Weed control in carbon-vermiculite protection experiment] Treatment Weeds per square foot 19 days after herbicide application Pound/ Lambs- Carpet- Pig- Velvet- J imson- Purs- Herbicide acre Grass quarter weed weed leaf weed lane Check 3. 59 3. 03 6. 35 3. 14 1. 11 458 .183 A 8 .28 ".03 ".18 ".08 ".17 .01 B 2 .00 .00 .00 ".00 ".02 ".00 .00

Significantly difierent from control at .05 level.

"Significantly difierent from control at .01 level.

pound/Acre Herbicide A in a field experiment. However, unprotected beets and cucumbers showed significant injury as reflected in stand counts and fresh weights at both rates while tomatoes only showed injury at 12 pound/Acre (FIGS. 1 through 3). The carbon-vermiculite treatment was effective in protection at 4 pound/Acre for beets and cucumbers, but showed a significant decrease in fresh weight at 12 'pount/Acre. However, at 12 pound/Acre some yield was obtained, whereas no yield was obtained with the untreated TABLE 3 [Number of hills with live plants days after planting] Rate. Oarbon- Hills/10 foot row with live plants pound/ vermicu- Herbicide acre lite Soybeans Tomatoes Cucumbers Barley 0 6.25 ab 12.50 a 17.00 a 0 7.00 a 6.00 b 14.25 ab 8 2.75 ab .00 c 7.50 be 8 4.75 ab 3.25 be 11.75 abs 2 .00 be .00 c 6.25 c 2 .00 be 1.50 c 10.00 abc NOTE.-Any two means followed by the same letter(s) are not significantly difierent at the 5% level according to Duncan's new multiple range test.

Norm-Any two means followed by the same letter(s) are not significantly diflerent at the 5% level according to Duncan's new multiple range test.

plants. Tomatoes showed protection at 12 pound/Acre. Pro- 'tectionwas also observed on cabbage, but insect damage made the results with this crop too variable. Weed control data (Table 1) showed that the carbon-vermiculite treatment resulted in less weed control and this was especially evident at the 4 pound-Acre rate.

m TABLE 1 Soybeans were significantly protected from Herbicide B- which was especially striking since total inhibition resulted when activated carbon-vermiculite was not applied. Tomatoes showed limited protection when Herbicide A was applied. Cu+ cumbers were not significantly protected, but while Herbicide B and Herbicide A gave total inhibition of the unprotected [Weed control in carbon-vermiculite protection experiment against two rates 0! Herbicide A] Treatment Weeds per square foot 22 days alter herbicide application Carbonvermicu- Herbicide A lite Purs- Pig- Smart- Velvet- Lambs- Carpetpound/acre mixture lane weed Grass weed lea! quarter weed Significantly different from the control at the .05 level.

"Significantly diflerant from the control at the .01 level.

seedlings the carbon-vermiculite treatment resulted in a small yield. The carbon-vermiculite treatment gave limited protection to barley when both Herbicide A and Herbicide B were applied. While this experiment was not totally successful it demonstrated that protection could be obtained even under severe conditions. Also, it may point out that a definite need exists for a better herbicide for this principle.

A greenhouse experiment apparently presented less severe conditions as evidenced by the protection obtained (FIGS. 4 through 8). Here protection was observed for cucumbers and tomatoes at 16 pound/Acre of Herbicide A with the carbonvermiculite treatment while 4 pound/Acre gave severe to total inhibition when there was no protection (FIGS. 4 and 5). Herbicide B at 8 pound/Acre did not harm tomatoes with the carbon-vermiculite treatment whereas untreated tomatoes were killed at Va pound/Acre (FIG. 6). Cucumbers and soybeans were protected well from 4 pound/Acre of Herbicide B with the carbon-vermiculite treatment while complete kill occurred at 2 and 4 pound/Acre respectively when unprotected (FIGS. 7 and 8). The greenhouse data show that protection occurs at herbicide rates where good weed control could be attained. The cost per acre of the activated carbon-vermiculite mixture is reasonable for horticultural crops and season long weed control is possible, this seed protective treatment shows promise for field application. Precision seeding is possible because of more even emergence. Also, the carbon residue in the soil is relatively low which is important because a high residue interferes with weed control in following years by adsorbing the herbicides placed in the soil.

Although the hill method described above for protecting seeds from certain pre-emergent herbicides is a satisfactory approach to the problem, another way of realizing the invention is by incorporating the seed and activated carbon-vermiculite in a compressed wafer, preferably using a liquid fertilizer for a binder, one useful finder being of lO34-0 composition. Various pressures were used in making wafers ranging from 30 to 2,100 p.s.i. Pressures of more than 300 p.s.i. were found to cause decreased seed emergence. The wafers were made, and the pressure applied, in a small cylinder and piston device, in which the loose mixture was placed and the seeds were implanted at the approximate center of the wafer by glass tube. Another method of emplacing the seed is to thoroughly mix the seeds with the carbon-vermiculite binder ingredients, as in a tumbler, for example, and then compress the resulting mixture.

In a greenhouse study wafers were made using only ver miculite and the emergence of tomato seedlings was recorded and the test results are shown in Table 5 as follows:

TABLE 5 Number of Tomato Seedlings from Vermiculite Wafers Wafers consisting of L5 grams of vermiculite were compressed at different pressures to form wafers one-fourth one half and five-eighths inches thick and three-fourths inch diameter. Liquid fertilizer 10-34-0 at 0.1 ml. per wafer was used as the sole binding agent. Four seeds of Heinz 1,370 were placed in each wafer. The seedings were made in four replicates. From Table 5 it appears that pressures of less than TABLE 6 The Number of Plants and Fresh Weight of Tomato Seedlings 22 Days After Seeding Activated Carbon-Vermiculate Wafers.

Activated Carbon Pressure Thickness Number of FEE per liter |J.S.i. inches Plants Weight Vermiculate grams Emerged grams l5 2'1 it 13 1a.: 30 l l A 12 16.7 60 127 V1 4 0,4 Control (Conventional Seeding] l5 20.7

It appears that 15 grams of activated carbon per liter of vermiculite is optimum. It was also noted that where carbon was used the seedlings emerged earlier.

Tomato seeds in activated carbon-vermiculate wafers were seeded in four replicates using Heinz L370 seeds and 15 grams of activated carbon per liter of vermiculite. These seedlings were made in soil with different rates of Herbicide B plus a control seeding. From FIG. 9, 1e pound of Herbicide B per acre destroyed all the tomato seedlings without activated carbon for protection. With the activated carbon wafers the tomato seedlings were given protection at an application of 2 pound per acre of Herbicide B.

Similar wafers as above were made and seeded in the field at the Purdue ONeal farm in a silt loam soil. The herbicides used were Herbicide B, 4-bis(isopropylammo) -6 '(methylthio) -s triazine, (hereafter called Herbicide C"), and 3 -amino -2, 5- dichlorobenzoic acid, (hereafter called "Herbicide D"). The wafers were seeded l 1 hills per plot in four replicates (l hill 1 wafer). Four seeds of Heniz 1,370 were used in each wafer. Table 7 indicates a very definite increased emergence of the seed wafers compared to the conventional direct seeding.

TABLE 7 Increase in Emergence of Tomato Seedlings with the Wafer vs. Conventional Direct Seeding in the Field Without FIG. 10 shows the comparison of the above seedings and herbicides by number of hills.

Seed wafers are prepared with two cucumber seeds, variety Wisconsin SMR-IS, starter fertilizer, 15 grams activated car- 100 pounds and a wafer one-half to five-eighths inches thick bon per liter of vermiculite. These wafers were seeded at the Purdue ONeal farm in a sandy loam soil with the herbicides, carbon tends to cause iii'ferifiefiiiir'iflfififi'e'sd to rise (methylsulfonyl) -2, 6- dinitro N, N di ro ylaniline, which aids emergence. The high phosphorous liquid -34-0 (hereafter called Herbicide E"), and dimethyl fertilizer in direct contact with the seed prevents any delay tetrachloroterephthalicalate, (hereafter called Herbicide due tolack Ofnutfients- F"). 5 With the seed wafers there is no problem of soil crusting,

' delaying ofemergence.

TABLE 8 Activated carbon tends to protect young seedlings from herbicide damage. The degree of herbicide protection depends on the type and rate of herbicide used and the amount of ac- 10 tivated carbon incorporated in the wafer. However, with 60 Fresh Weight ofcucumbel'l Seedlings as Influenced y grams or more of activated carbon per liter of vermiculite Different Herbicides when Conventionally Direct Seeded or plant emergence d growth were d rea ed.

Seeded in wafers- The invention may be practiced as shown in FIG. 11

wherein the compressed tablet 1 has seeds 2 at its approximate v M I V 7 center surrounded by compressed activated carbon 3 and ver- Pmmd wafers miculite 4, and all of this is held together by a binder (not v Era-[PS shown) which is preferably liquid fertilizer. Y Another mode of practicing the invention is shown in FIG. 2 3 1 {2 12 wherein a water-soluble mat 5 is used to encapsulate the None 0 H00 1000 activated carbon-vermiculite mixture at 6, and the mixture if whom" SMMS may be made into tablets before encapsulation, or the tablet r step may be omitted, depending on the desired mode of manu- Table 8 indicates that there is significant protection to cuf w f the water l bl cumber seedlings. The control weights were low due to com-, 7' petition of the plants with weeds.

Four essentials'of direct seeded vegetables, precision placei ment of the seed, application of anticrusting materials, supply- We claim:

1. A herbicide-resistant seed wafer comprising at least one seed encased in a mixture of a water-soluble nutrient binder,

ing Starter fenilizer and protecting f young vegetables venniculite,and activated charcoal, the ratio of vermiculite to.

seedlings from herbicide damage, can be accomplished in one charcoal being in a Tang? o from about to P y seeding operation using the wafers. weight, said mixture being compressed about the seed sufii- Seed environment is very important for quick emergence: ciently to form a cohesive wafer.

With seed wafers the seed environment can be controlled. The s It a a: 

